If they are interesteed in you enough to carry a conversation with you at least give him/her a chance to be interested in you. I know, being a girl, that they love to speak of themselves, but I also know for a fact that guys need to feel like I they are worth your time. If you are talking about yourself give him a chance to catch up and if you are blowing you rown horn give her a chance to blow hers.
^.^